The present application relates to an air-bag, and more particularly relates to an air-bag arrangement comprising a gas-supply duct.
It has been proposed previously to provide various forms of airbags with a substantially rigid gas-supply duct configured to direct a flow of gas from an inflator or gas generator through specific regions of the air-bag which are to be inflated.
For example, various designs of “inflatable curtain” have been proposed. Such an inflatable curtain is an air-bag which is initially stored within the roof lining of a motor vehicle immediately above the door openings, the air-bag inflating in response to a signal from an appropriate sensor to form a “curtain” lying adjacent a side window of the vehicle. Frequently, an air-bag of this type comprises two discrete chambers for inflation. One chamber being configured to lie adjacent the front side-window of the vehicle, and the other chamber being configured to lie adjacent the rear-side window of the vehicle upon inflation of the air-bag. In order to use a single inflator or gas generator to inflate both discrete chambers of the air-bag, it is convenient to arrange the inflator or gas generator in the region of the “B-pillar” of the motor vehicle structure, i.e. the pillar extending vertically upwardly between the front and rear side windows of the vehicle.
As will therefore be appreciated, in order to ensure proper inflation of both of the discrete chambers of the above-mentioned inflatable curtain, gas generated by the single gas generator must be directed towards each discrete chamber. However, because an inflatable curtain-type air-bag must be inflated in a very short period of time if it is to be of value in a side impact situation, the gas generator must produce a very large volume of gas in a very short period of time. The resultant flow of gas is very aggressive and can damage the inflatable curtain if not carefully directed into the interior of the inflatable curtain. It is known to provide a substantially rigid gas-supply duct, extending from the single gas generator, in order to direct the flow of gas into the interior of the inflatable curtain.
DE 20016717U1 discloses an arrangement comprising a pair of divergent gas-supply ducts, each configured to direct gas from a common gas generator towards a respective region of the inflatable curtain. However, the provision of two gas supply ducts adds complexity and expense to the arrangement.
DE 19850448A discloses a single gas supply duct configured to provide a flow of gas along two flow paths, into separate air-bags. The two flow paths are substantially perpendicular to one another.
The present invention seeks to provide an improved air-bag arrangement.